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Oxidized bitumen 90/40 is a high-softening-point, air-blown asphalt designed for industrial waterproofing, roofing membranes, pipe coating, joint filling, and protective compounds. It offers excellent thermal stability, controlled flexibility, and strong adhesion to different surfaces. This grade is ideal for contractors, membrane producers, pipe-coating factories, and insulation manufacturers who need a stable binder that performs consistently under heat and load. In real operations, it matters because it reduces cracking, improves coating durability, and delivers predictable behavior during melting and application.
Oxidized bitumen 90/40, also known as blown bitumen 90/40, is produced by passing hot air through penetration-grade bitumen under controlled temperature and pressure. During this process, the internal structure of the bitumen changes. As a result, the material becomes harder, its softening point increases, and its penetration value decreases.
The numbers 90/40 typically indicate:
Softening Point: Around 90°C
Penetration: Around 40 dmm (at 25°C)
This balance creates a material that remains firm under high temperatures while still keeping enough flexibility to avoid brittle failure.
In simple terms, oxidized bitumen 90/40 is engineered for stability. It does not flow easily under heat, and it does not crack quickly under moderate stress.
In industrial environments, materials must perform under pressure. Roofing systems face direct sunlight. Pipelines deal with soil pressure and temperature changes. Waterproofing layers remain under constant stress.
Oxidized bitumen 90/40 solves several practical problems:
Prevents excessive flow in hot climates
Reduces deformation under weight
Improves resistance to water penetration
Enhances long-term durability
Because of its high softening point, this grade performs better than softer penetration grades in high-temperature regions. For example, while bitumen 60/70 is commonly used for road construction, it is not suitable for roofing membranes exposed to direct sun for long hours. Oxidized grades are specifically modified to handle those conditions.
This grade is not designed for paving roads. Instead, it is widely used in industrial manufacturing and protective systems.
Manufacturers use oxidized bitumen 90/40 in APP and SBS membrane production. Its high softening point ensures the membrane does not sag or deform under heat.
Moreover, it provides strong bonding between layers and reinforcement materials.
In pipeline protection, stability is critical. Soil pressure, moisture, and temperature variations constantly challenge the coating layer.
Oxidized bitumen 90/40 forms a tough, protective barrier. It resists water ingress and helps prevent corrosion.
Basement waterproofing, foundation sealing, and concrete surface protection all require a material that remains stable over time. This grade creates a durable layer that resists moisture and environmental stress.
It is also used in industrial sealants, joint fillers, and expansion compounds where controlled hardness and heat resistance are required.
Understanding technical performance helps buyers make informed decisions.
Typical properties include:
Softening Point: 85–95°C
Penetration at 25°C: 35–45 dmm
Flash Point: Above 250°C
Solubility in CS₂: >99%
Ductility (at 25°C): Moderate
These values may slightly vary depending on production method and raw material quality.
The most important factor is consistency. Industrial users require stable parameters from batch to batch. Variations can affect membrane flexibility, coating thickness, and performance under load.
The air-blowing process must be controlled carefully. Temperature, airflow rate, and oxidation time all influence the final structure.
If oxidation is too aggressive, the product becomes brittle. If insufficient, the softening point remains too low.
Reliable producers maintain:
Continuous temperature monitoring
Controlled airflow
Laboratory penetration and softening point testing
Batch-based quality documentation
Quality control is not optional. In large export shipments, buyers often request independent inspection before loading.
Although oxidized bitumen 90/40 is stable, proper handling ensures safety and performance.
It should be heated gradually and uniformly. Overheating can damage its internal structure and reduce performance.
Recommended heating temperature usually ranges between 150°C and 180°C, depending on application.
Store in dry, covered areas
Avoid direct moisture exposure
Use proper insulation for bulk storage tanks
During application, maintain consistent temperature to ensure proper flow and adhesion. Uneven heating can create weak bonding points.
Choosing the correct grade depends on application.
Penetration Grades: Softer, mainly used for road construction.
Oxidized Grades: Harder, suitable for roofing and industrial protection.
For example, bitumen 75/25 has a higher softening point and lower penetration compared to 90/40. Therefore, 75/25 is harder and more heat-resistant but less flexible. Meanwhile, 90/40 provides a balanced structure for applications requiring moderate flexibility and high stability.
Each grade serves a specific purpose. Using the wrong grade can lead to premature failure.
Suppliers typically offer oxidized bitumen 90/40 in:
25 kg or 50 kg kraft paper bags
180 kg drums
Jumbo bags
Bulk tanker shipments
The choice depends on buyer capacity and project scale.
For large membrane factories, bulk shipments reduce cost and handling time. Smaller contractors may prefer bagged material for easier storage and controlled usage.
The demand for oxidized bitumen 90/40 remains strong in regions with high temperatures and growing infrastructure.
However, industrial buyers always monitor bitumen price trends. Raw material costs, crude oil fluctuations, and regional supply chains influence final pricing.
Bulk purchasing often provides better cost efficiency. Moreover, long-term contracts reduce exposure to market volatility.
Even high-quality materials can fail if misused.
Cause: Application temperature too low or excessive oxidation.
Solution: Maintain proper heating and verify penetration value before use.
Cause: Incorrect grade selection.
Solution: Ensure softening point matches climate conditions.
Cause: Contaminated surface or insufficient heating.
Solution: Prepare surface properly and apply at recommended temperature.
Understanding these issues reduces risk and improves project outcomes.
Like all bituminous materials, oxidized bitumen 90/40 must be handled carefully.
Use protective gloves and clothing
Avoid inhalation of fumes during heating
Ensure proper ventilation
Follow local safety regulations
Modern production facilities also focus on emission control during the oxidation process.
In B2B supply chains, reliability is more important than marketing claims.
Contractors and manufacturers need:
Stable technical properties
On-time delivery
Clear documentation (TDS, MSDS, COA)
Transparent communication
Inconsistent batches create production delays and increase cost.
Therefore, selecting an experienced supplier reduces operational risk.
You should consider this grade if:
Your project faces high temperature exposure
You need a stable roofing binder
You require durable pipe coating
You manufacture waterproofing membranes
You need controlled hardness with moderate flexibility
It is not suitable for road paving or heavy traffic asphalt mixtures. For those applications, penetration grades like bitumen 60/70 remain the preferred choice.
Oxidized bitumen 90/40 is a practical industrial material designed for stability and durability. It performs reliably in roofing membranes, pipe coatings, and waterproofing systems. Its balanced structure provides heat resistance without becoming excessively brittle.
In real industrial operations, material selection affects long-term performance. Choosing the correct grade prevents premature failure, reduces maintenance cost, and improves project reliability.
Understanding specifications, application conditions, and supply quality makes the difference between short-term results and long-term success.
For buyers, engineers, and procurement managers, oxidized bitumen 90/40 remains a dependable solution when heat resistance and structural stability are essential.